I am doing a very simple simulation in COMSOL consisting of piezo, matching layer and water. It calculates transmission coefficients for a range of frequencies given a constant matching thickness. The maximum of the curve matches with the analytical result ( Which I am pretty sure is right since it matches with the experiment) but the minimum values differ by 50%. i don't know why it is happening? Can anybody help me with that?
Hi,
It's difficult to answer without seing the exact problem, maybe you could post at least your non-matching curves and some informations on the layer and piezo dimensions ?
As for the problem, remember that piezos are assumed lossless by default, and the same holds for pressure waves. Does your analytical result account for dissipation ?
Hello Oliver,
Please find the attached curves for analytical and FEM. Please note that it's an acoustic model. So I have not modeled any piezo, it is just an acoustic layer. The first layer is of piezo, then matching layer, after that a soft tissue and the bone. The transmission coefficients are calculated after the bone layer, which consists of soft tissue.
Best regards,
Shreyank Gupta
Dear Mohammad,
I did extremely fine meshing which includes per wavelength 20 elements. I don't think so it is a problem of grid or meshing
Best regards,
Shreyank Gupta
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